Here's the process of installing the 32ch modification to the Go App on an IOS device, using Itunes on a PC.
You don't need the craft turned on for this. You do not need to have the Go app launched. Simply connect your IOS device to your PC with a USB cable and launch iTunes on the PC. You'll need to unlock the IOS device with your password to give iTunes access to the device.
1. Click the iPad icon
Make sure APPS is selected, so the apps show up for your IOS device.
Scroll down the screen till you see FILE SHARING for your IOS device. Click DJI GO
With DJI app highlighted, click "Add File"
Navigate to the file you downloaded and click to highlight. The file name must be .DJI.configs (two dots are important). Click Open.
You will get a dialog asking you if you want to replace an existing file with the same name. Click Replace
After clicking "Replace" the file transfer happens very quick. You're done.
There is no confirmation the file was replaced. To confirm the modification worked, launch the GO APP on your IOS device (no need to have craft turned on). Click the HD icon to see channel selector. In Custom mode you should see 32 channels now. Touch and slide the channel numbers left and right to see all 32 channels. Select the channel that's the least busy when prepping your craft.